Mt. St. Helen’sMt. St. Helen’sWashington StateWashington StateKatie Reibling & Jessie RadelKatie Reibling & Jessie Radel

First signs of lifeFirst signs of life

Thursday, March 20Thursday, March 20th th 1980 19804.1 magnitude4.1 magnitudeearthquake centered earthquake centered beneath the volcano. beneath the volcano. Most northwest newspapers Most northwest newspapers completely ignored this completely ignored this earthquakeearthquakePresident Carter's President Carter's announcement of the announcement of the Moscow Olympics boycott Moscow Olympics boycott dominated the newsdominated the news

March 27March 27thth-30-30thth1980 1980

March 27th, first puff March 27th, first puff of ash. of ash. The small explosion The small explosion left a 250 foot wide left a 250 foot wide crater in the otherwise crater in the otherwise perfect cone. perfect cone. On March 30th there On March 30th there were a record 79 were a record 79 earthquakes recorded earthquakes recorded on the mountain on the mountain

April 3April 3rdrd 1980 1980

the first harmonic tremors the first harmonic tremors were recorded signaling were recorded signaling the movement of magma the movement of magma somewhere deep within somewhere deep within the dome. the dome.

The crater was by now The crater was by now 1,500 feet wide. 1,500 feet wide.

Explosions of ash, rock Explosions of ash, rock and ice chunks were a and ice chunks were a daily occurrence.daily occurrence.

The bulgeThe bulge

In April a noticeable In April a noticeable bulge formed on the bulge formed on the north side of the north side of the mountain.mountain.

Building of magma, Building of magma, hot gasses and hot gasses and pressure pressure

Grew five feet per dayGrew five feet per day

The Eruption May 18The Eruption May 18thth 1980 1980

statisticsstatistics

Largest land slide in historyLargest land slide in history

5.1 magnitude quake5.1 magnitude quake

Elevation dropped from 9,677 to 8,363 ft.Elevation dropped from 9,677 to 8,363 ft.

All of the rock ash melted snow and debris All of the rock ash melted snow and debris rushed down the mountain into the Toutle River rushed down the mountain into the Toutle River Valley at speeds higher that 175 mphValley at speeds higher that 175 mph

ImpactsImpacts

57 People were killed57 People were killed

5,000 black tailed deer,1,500 Roosevelt Elk, 5,000 black tailed deer,1,500 Roosevelt Elk,

200 Black Bears, millions of small animals200 Black Bears, millions of small animals

Toutle River valley Toutle River valley

3 billion dollars in damage3 billion dollars in damage

Plate TectonicsPlate Tectonics

The Juan de Fuca plate is subducting under the N. The Juan de Fuca plate is subducting under the N. American plate American plate Magma moved into the shallow part of the volcano Magma moved into the shallow part of the volcano through out the many minor eruptionsthrough out the many minor eruptionsSo much pressure made the north So much pressure made the north

bulge give out. bulge give out.

Will it Happen Again?Will it Happen Again?

The slow collision of the North American Plate The slow collision of the North American Plate and the Juan de Fuca plate is causing the Juan and the Juan de Fuca plate is causing the Juan de Fuca to slowly move beneath the Pacific de Fuca to slowly move beneath the Pacific NorthwestNorthwest

Scientists predict it will erupt again Scientists predict it will erupt again

they are not sure when or how much volcanic they are not sure when or how much volcanic activities it will bring.activities it will bring.

Monitoring Mt. St. Helens todayMonitoring Mt. St. Helens today

http://www.fs.fed.us/gpnf/recreation/currenhttp://www.fs.fed.us/gpnf/recreation/current-conditions/t-conditions/

websiteswebsites

http://www.olywa.net/radu/valerie/mshafter.htmlhttp://www.olywa.net/radu/valerie/mshafter.html??

http://www.lincoln.smmusd.org/science/7th%20Grade/http://www.lincoln.smmusd.org/science/7th%20Grade/Earth/palosverdesfieldtrip/graphics/plate_boundaries.gifEarth/palosverdesfieldtrip/graphics/plate_boundaries.gif